N2 - Two methods for detailed characterization of the process of oxygen exchange between the gas phase and a mixed conducting solid oxide are discussed. First, the use of solid electrolyte probes for<br/>measuring the change in oxygen activity over the surface of a mixed conductor is presented and advantages of the technique discussed. Secondly, the use of thin film model electrodes is treated.<br/>Studies of thin films applied by PLD on both sides of a YSZ single crystal are presented for three different film materials; La0.85Sr0.15MnO3, La0.6Sr0.4Fe0.8Co0.2O3 and La0.6Sr0.4CoO3. Variations<br/>in electrode performance with film structure are elucidated and the rate of the exchange process on the films is compared to that observed on bulk samples.

AB - Two methods for detailed characterization of the process of oxygen exchange between the gas phase and a mixed conducting solid oxide are discussed. First, the use of solid electrolyte probes for<br/>measuring the change in oxygen activity over the surface of a mixed conductor is presented and advantages of the technique discussed. Secondly, the use of thin film model electrodes is treated.<br/>Studies of thin films applied by PLD on both sides of a YSZ single crystal are presented for three different film materials; La0.85Sr0.15MnO3, La0.6Sr0.4Fe0.8Co0.2O3 and La0.6Sr0.4CoO3. Variations<br/>in electrode performance with film structure are elucidated and the rate of the exchange process on the films is compared to that observed on bulk samples.